ⅰ 语言知识及应用(共两节，满分45分) 第一节 完形填空(共15小题；每小题2分，满分30分) 阅读下面短文，掌握其大意，然后从1~15各题所给的a、b、c和d项中，选出最佳选项，并在答题卡上将该项涂黑。 when you are having class in the early morning, it is not unusual to notice your classmate sitting beside you yawning. he 1 that he didn’t have a sound sleep the night before. many 2 don’t get adequate sleep because they are burdened with too much homework, which keeps them up at night doing countless exercise. some teens cannot 3 at night even when they want to so much. researches show that during your teenage years, the body’s biological clock is ___4_ ,telling you to sleep later at night and wake up 5 in the morning. but 6 in the body clock aren’t the only reason teens lose sleep. lots of people have insomnia（失眠）.
